| 摘要 |
A computerized method for performing a measurement of an axisymmetric part such as a helical coil spring with an axis of cylindrical symmetry. Digital image data of the axisymmetric part is captured at a number of angles about the axis. For each angle, edges of the part are imaged in the digital image data, producing edge data; and eccentricity, concentricity and parallelism of the axisymmetric part is measured by calculating based on the edge data. The calculation is performed by fitting the edge data to an amplitude coefficient of a periodic function, e.g. sine function, of the angles, and the measurement is derived from the amplitude coefficients. The background of the part is illuminated which accentuates the edges. The measurement is compared with a specified tolerance of the part and a pass/fail criterion is generated and displayed.
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